Mercedes GLC — MPG & Fuel Costs 2025
Mercedes' popular mid-size SUV. Quiet, highly luxurious, and offering efficient diesel options for long-distance drivers.
TL;DR
30 MPG
Real-world petrol
40 MPG
Real-world diesel
66L
Tank capacity
£90.29
Full tank (petrol)
20.7p
Per mile (petrol)
Real-World Fuel Economy: The Mercedes GLC achieves an estimated 30 MPG (petrol) and 40 MPG (diesel) in real-world UK driving conditions, accounting for a 12% WLTP real-world penalty.
Forecourt Fuel Cost: Refueling the 66-litre tank completely costs approximately £90.29 (petrol) or £93.79 (diesel) at average UK fuel price rates.
Fuel economy at a glance
30
Real-world MPG
Petrol
36.2
Official WLTP
Petrol
40
Real-world MPG
Diesel
47.9
Official WLTP
Diesel
Annual fuel costs by mileage
| Annual mileage | Petrol | Diesel |
|---|---|---|
| 5,000 miles/yr | £1036 | £807 |
| 7,400 miles/yr(UK average) | £1534 | £1195 |
| 10,000 miles/yr | £2073 | £1615 |
| 15,000 miles/yr | £3109 | £2422 |
| 20,000 miles/yr | £4146 | £3230 |
| Full tank (66L) | £90.29 | £93.79 |
| Cost per mile | 20.7p | 16.1p |
Based on UK average fuel prices: petrol 136.8p/L · diesel 142.1p/L. Prices updated regularly.
How does the GLC compare?
Tips to get better MPG from your GLC
4MATIC all-wheel drive is standard; drive smoothly to offset the mechanical driveline drag.
Use Eco mode to enable sailing/coasting functions on the motorway.
Cruising at 65 mph on the highway rather than 75 mph improves fuel economy due to the GLC's SUV profile.
Is the cheaper petrol station worth it?
In a Mercedes GLC achieving ~30 MPG real-world, if you fill 53 litres and the alternative station is 10p/litre cheaper:
£5.30
Gross saving on fuel
£0.62
Cost of 3-mile detour
£4.68
Net saving ✓
You could drive up to 26 miles round-trip before the saving disappears entirely.
Calculate for your exact situationPopular variants
Frequently asked questions
What is the real-world MPG of the Mercedes GLC?
The Mercedes GLC achieves approximately 30 MPG in real-world petrol driving — around 12% lower than the official WLTP figure of 36.2 MPG due to real driving conditions. Diesel variants achieve around 40 MPG real-world.
How much does it cost to fill a Mercedes GLC?
The Mercedes GLC has a fuel tank of 66 litres. At the UK average of 136.8p/litre for petrol, a full tank costs approximately £90.29. Diesel costs approximately £93.79 for a full tank.
What is the annual fuel cost for a Mercedes GLC?
At the UK average annual mileage of 7,400 miles and current petrol price of 136.8p/litre, a Mercedes GLC costs approximately £1534 per year in fuel. At 10,000 miles/year the cost rises to £2073. Actual costs vary with your driving style and mileage.
Is it worth driving to a cheaper petrol station in a Mercedes GLC?
In a Mercedes GLC doing ~30 MPG real-world, driving 3 miles round-trip to save 10p/litre on a 53-litre fill nets approximately £4.68 after the extra fuel cost. You could drive up to 26 miles before the saving is eaten up. Use the WorthThePump calculator for your exact situation.
How much does the Mercedes GLC cost per mile in fuel?
The Mercedes GLC costs approximately 20.7p per mile in petrol at current UK prices. Over a typical commute of 30 miles per day, that is approximately £6.21 per day in fuel.
What is the WLTP MPG figure for the Mercedes GLC?
The official WLTP fuel economy figure for the Mercedes GLC is 36.2 MPG. However, real-world MPG is typically 10–15% lower than WLTP due to cold starts, air conditioning, motorway speeds, and varying loads. WorthThePump uses a 12% real-world penalty to give a more accurate estimate.
Related guides
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